$ time curl http://whoami.prod4.fn61.net/
... snipped
<title>whoami.prod4.fn61.net | 524: A timeout occurred</title>
... snipped
real 1m40.114s
user 0m0.008s
sys 0m0.004s
I ran this at the same time from the exact same computer:
$ time curl -H 'Host: whoami.prod4.fn61.net' http://52.233.163.84/
Hostname: c70e24a08b3a
IP: 127.0.0.1
IP: ::1
IP: 10.0.0.5
IP: 10.0.0.4
IP: fe80::42:aff:fe00:5
IP: 172.18.0.4
IP: fe80::42:acff:fe12:4
GET / HTTP/1.1
Host: whoami.prod4.fn61.net
User-Agent: curl/7.47.0
Accept: */*
Accept-Encoding: gzip
X-Forwarded-For: 10.255.0.3
X-Forwarded-Host: whoami.prod4.fn61.net
X-Forwarded-Proto: http
X-Forwarded-Server: a38c52a7b8f3
real 0m0.100s
user 0m0.000s
sys 0m0.004s